Saeviomagy
Adventurer
Play a lore college bard, take perform(oratory) and pick up find steed (2nd level, call an elemental, angelic or demonic version of a steed), find familiar (for your imp), conjure animals and conjure elemental (of some variety) with your cross-class spells.
Find steed gives you a combat-worthy creature that you can control, dismiss and re-summon.
If you're lucky, you might be able to get your DM to expand the lore bard's bardic music usage to include debuffing saves (possibly in exchange for one of it's other abilities) which lets you use planar binding.
In general though, don't expect to be binding things which would be a challenge to your party.
Find steed gives you a combat-worthy creature that you can control, dismiss and re-summon.
If you're lucky, you might be able to get your DM to expand the lore bard's bardic music usage to include debuffing saves (possibly in exchange for one of it's other abilities) which lets you use planar binding.
In general though, don't expect to be binding things which would be a challenge to your party.
